Dental drilling-tool



w. E. CHESTER. DENTAL DRILLING TOOL.

APPLICATION FILED JUNE 27, I917- Patented Mar. 9,1920.

III

I o 122 I I a full, clear, and exact description, refer-- UN STA ES OFFICE WILLIAM; E. CHESTER, 0F Nonwoon. 01110.

DENT L nmLnfne roon. r

dent ofNorwood, in the county of Hamiltonand State of Ohio, have invented certain new and useful Improvements in Dental Drilling-Tools, of which the following is ence being had to the accompanying drawforming part of this specification.

y invention relates to tools for use in.

drilling out cavities in tooth roots prepara tory to the insertion-therein of a crown re taining post. The post itself forms no part of this inventionand 'isflnot illustrated in the drawings, the object of this invention being to provide a drill that will form in the root'of a tooth,'a drilled-out countersunk recess in the exposed end of the root, a drilled-out pulp canal extending inwardly from the root recess at the center of the recess, and when desired, a groove in the root around the walls of the countersunk recess.

A chief object of this invention is to provide a practical tool for this purpose which is adaptablefor uses in many different cases by the simple interchange of parts, and thus avoid the necessity of the dentists supplying himself with all possible sizes of complete tools; Another'object is'the provision of a removable trephine or hollow circular drill for the tool which can be put in place when it is desired to drill the outer groove in the case of the countersunk recess.

The said objects and other advantages to be noted I accomplish by that certain con struction and arrangement of parts to be hereinafter more specifically pointed out Fig. 4 is a longitudinal section through a root prepared by the use of the tool.

Fig. 5 1s a longitudinal central sectio through a modified form of tool.

Figs. 6 and 7 are a sideelevation, and a centrally broken away elevation from an other side, of a third modification. Fig. 7 is taken on the line 7, 7 of Fig. 6.

' j Specification of Letters fatent. .7

-10 for the root canal.

Patented 9, 1920.

. Application flledJ'une 27,1917; Serial No. 177,172.

The form of the desired cavity to be pre pared by the use of the tool is shown in F ig. 4, wherein the root 1 is shown having the pulp canal 2. In the outer end of the root isto be cut the countersunk .rece'ss 3,-

and around the walls of the recess the groove 4 is to be cut. From the centerof the recess the pulp canal is to be drilled out as at 5. The tool so prepared may be used very advantageously in the mounting of a demountable post therein, s'aidpost to'retain a crown.

There are a number of ways inwhich such a recess can be used, one of them being to provide a post for the dentist corresponding to'the size of tool or tool section used by him. This post will have a shoulder to fit.

the recess, anda central extension which will fit the drilled out pulp canal. The post may also have a flange around the periphery of its shoulder which will fit the groove around the countersunk recess.

It can be seen that a drillingtoolthat has all'of its operations performed atone time,

by united parts for the different cuttings, can easily drill out a cavity which will fit a properly selected post, and thus that the insertion of the post is not likely to injure the tooth root by splitting or the like.

The tool comprises a shank 6, which in one form of the invention has its one end expanded as at 7 and cuton the end with cutting or drilling teeth 8. In this expanded end is formed'a recess 9 for receiving a drill This drill may be secured in the recess in any desired manner, such as, for example, it may be squared at its end 11, and the end 11 inserted in the recess and held with a small set screw 12. A mere tapered recess could be provided and the squared end made to a like taper (Fig. 7). The exact method is not essential. The shank and expanded end serve as a chuck to receive other tools as will be noted.

If preferable to the dentist, the drill mem ber 10 could be made integral with the shank (Fig. 5), and the recess drilling portion 7 provided with a hollow center to fit over the drill lO and snugly fit onto the shank 6.

The shank'could then be provided with a slot 13 to receive a pin 14 extending, inwardlzy into the hollow bore of the said part H The essential feature'of the above structure is that the recess drilling portion and the pulp canal drilling portion are separable from each other and the dentist need provide himself with but one shank member with whichever part is integral-with=it and can select the other of the two members which he may desire to use. The point" are separable shouldabe marked with small numbers'tocorrespond with the desired dimension ofposts, to facilitate the selection.

Otherwise the selection of theproper post p and tool depends on the nature of the work,

to be done, and. it should not be understood that any one of my devices could be used? This, could not be for. all possible cases. true, and the dentist employing my method of drilling. teeth: for artificial crowns will have to. have several shank members of. dilferent sizes and the removable. drillmenr. bers ina more or less wide selection.

The cutting. of the outer groove. around the-walls of the. countersunk recess can be done with aremovable tool so thatwhen this is not desired by the dentist, he need not employ this section of the tool at all. The tool used resemblesna trephine, in being a thin cylinder of metahhaving a; toothed edge 15 and abody portion '16. It is to be slipped over the "recess driller portion, and preferably has an inwardly extending pin .or pins 17 that engage in grooves cutin the outer.

surface of the recess driller member.

I have found that there is no need of retaining .the trephine against sliding endwise ofithe rest of thedrill and that all that is necessary is to preserve it against rotation or tipping. Thus its fit on the shank of the recess driller should be close, and there liho'ildbe a pin and slot connection of some Asshown'in Fig. 6, the trephine is slipped on over the recess driller 7, 8, and held against rotation by means of extensions'l8' that slide into. shallow cuts 19 on the periphery of the said drill member, so as to be firmly clutched in place.

Having thus described. my invention, what I. claim as new and desire to secure by Letters Patent, is

1. A dental tool comprising essentially a chuck element, means on said chuck element for detachably securingthereto a pulp canal 1 drilling member andadditional meansthereon for detachably securing-thereto a recess drilling. member simultaneously with the pulpcanal drilling member. I 2. A dentaltool compr singa chuck elementhaving a recess cutting member thereon, a pulp. canaldrilling'member thereon, 3

and a -trepl-iine member thereon, two of these members at. least being demountably secured to the chuck element, andmeans for holding them in fixed relation to each otheron the chuck element, whereby operation of the element will operate said members simultaneously.

3. A dental drillingtool fordrilling out tooth roots comprising a tool for cutting a countersunk recess in "the head of'a root,

and for simultaneously. drilling out' the pulp canal thereof, a small "trephineof a size to fit closely around. the recess cutting portion of the tool, and'means forretaining said trephine against rotation on said portion, for the purpose described. I

. WILLIAM E. CHESTER. 

